Probing the dynamics of N-methylacetamide in methanol via ab initio molecular dynamics

2017 ◽  
Vol 19 (20) ◽  
pp. 12868-12875 ◽  
Author(s):  
Vivek K. Yadav ◽  
Michael L. Klein
Keyword(s):  
Molecular Dynamics ◽  
Ir Spectroscopy ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Two Dimensional ◽  
2D Ir ◽  
Vibrational Bands

Two-dimensional infrared (2D IR) spectroscopy of amide 1 vibrational bands provides a valuable probe of proteins as well as molecules such as N-methylacetamide (NMA), which present peptide-like H-bonding possibilities to a solvent.

scholarly journals The Thermal Stability of Janus Monolayers SnXY (X, Y = O, S, Se): Ab-Initio Molecular Dynamics and Beyond

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 101
Author(s):  
Yufeng Luo ◽  
Shihao Han ◽  
Rui Hu ◽  
Hongmei Yuan ◽  
Wenyan Jiao ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Thermal Stability ◽  
Ab Initio ◽  
Atomic Displacement ◽  
Ab Initio Molecular Dynamics ◽  
Maximum Temperature ◽  
Two Dimensional ◽  
Asymmetric Structures ◽  
Atomic Displacement Parameters ◽  
Thermal Stability Of

In recent years, the Janus monolayers have attracted tremendous attention due to their unique asymmetric structures and intriguing physical properties. However, the thermal stability of such two-dimensional systems is less known. Using the Janus monolayers SnXY (X, Y = O, S, Se) as a prototypical class of examples, we investigate their structure evolutions by performing ab-initio molecular dynamics (AIMD) simulations at a series of temperatures. It is found that the system with higher thermal stability exhibits a smaller difference in the bond length of Sn–X and Sn–Y, which is consistent with the orders obtained by comparing their electron localization functions (ELFs) and atomic displacement parameters (ADPs). In principle, the different thermal stability of these Janus structures is governed by their distinct anharmonicity. On top of these results, we propose a simple rule to quickly predict the maximum temperature up to which the Janus monolayer can stably exist, where the only input is the ADP calculated by the second-order interatomic force constants rather than time-consuming AIMD simulations at various temperatures. Furthermore, our rule can be generalized to predict the thermal stability of other Janus monolayers and similar structures.

Structural and electronic properties of organo-halide lead perovskites: a combined IR-spectroscopy and ab initio molecular dynamics investigation

2014 ◽  
Vol 16 (30) ◽  
pp. 16137-16144 ◽  
Author(s):  
Edoardo Mosconi ◽  
Claudio Quarti ◽  
Tanja Ivanovska ◽  
Giampiero Ruani ◽  
Filippo De Angelis
Keyword(s):  
Molecular Dynamics ◽  
Ir Spectroscopy ◽  
Ab Initio ◽  
Electronic Properties ◽  
Ab Initio Molecular Dynamics ◽  
Structural And Electronic Properties

We use CPMD simulations and IR spectroscopy to study hybrid perovskites considering their inherent ionic dynamics and the disorder of methylammonium cations.

Combustion Driven by Fragment-based Ab Initio Molecular Dynamics Simulation

2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Large Scale ◽  
Methane Combustion ◽  
Combustion Method ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Computational Time ◽  
Combustion Mechanism ◽  
Daily Lives

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.

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